Autorun a python script after reboot using rc.local

1. /home/lvtest/test/test.py　　

from datetime import datetime
now=datetime.now()
f=open('test.log','a')
f.write('%s '%now)
f.close()

2. edit /etc/rc.local with adding codes below:

　　cd /home/lvtest/test

　　su lvtest -c "python /home/lvtest/test/test.py"

　　exit 0　　# ? if it is necessary

3. Make your /etc/rc.local executable in case it is not already executable by

　　sudo chown root /etc/rc.local

　　sudo chmod 755 /etc/rc.local

4. Check everything works fine by executing

　　sudo /etc/rc.local start